A U.S. Pat. No. 2,417,650 discloses the most commonly used type of underwater electric-arc cutting and welding torch. In the U.S. Pat. No. 2,417,650 patent a torch is shown having a gas valve to admit a working fluid such as oxygen to the interior of the torch and to an internal bore in a cutting electrode. The electrode is held in the torch by a spring collet caused to circumferentially grip the electrode by means of a collet ring assembly. Means are provided to conduct electricity to the electrode and all electrical portions of the torch which could be touched by the user (diver) are provided with insulating coatings.
U.S. Pat. No. 3,751,625 discloses and claims a torch which was an attempted improvement over the torch of the U.S. Pat. No. 2,417,650 patent in the method of gripping the electrode. As pointed out in the specification of the U.S. Pat. No. 3,751,625 patent the frequent breaking and restarting of the electric arc could cause the electrode to loosen by turning of the collet assembly. This frequently happened because of the essentially line contact of the collet with the circumference of the electrode.
Torches of the prior art did not permit repositioning of the gas valve assembly and were usually made in multiple parts fitted together with mechanical locking means and an overall insulating envelope.
In addition to the foregoing patents U.S. Pat. Nos. 2,210,640; 2,396,307; 2,416,278; 2,462,463; 2,531,450; 3,223,817; and 4,131,780 disclose various types of underwater torches and their method of construction.